1. Field of the Invention
The present invention relates to a method for economically producing a resin composition pellet having a particular weight average fiber length, and furthermore having a particular fiber length distribution, by adding a fibrous filler to resin with an extruder. The resin composition pellet is suitable for molding a socket for a pin of a semiconductor device, in particular, a socket in which a pitch interval of a lattice area provided with a number of pin holes is 2 mm or less.
2. Description of the Related Art
Conventionally, in the case of kneading glass fibers or the like with a resin using an extruder, when injection molding is performed using a pellet obtained by inputting the resin through a main feed port and side-feeding fibers, under the condition that the melt viscosity of the resin is very low, the following problem arises. In the case of molding, for example, a socket of a semiconductor device with a narrow pitch interval, a completely filled molded product is not obtained since sufficient flowability is not obtained. Alternatively, the deformation amount of warping of a socket obtained due to the high injection pressure caused by forceful filling increases.
JP 06-240114 A (see claim 1, Table 1 of Example 1) describes that a resin composition pellet which is obtained by filling (A) 100 parts by weight of at least one liquid crystalline resin selected from a liquid crystalline polyester resin and/or a liquid crystalline polyester amide resin forming an anisotropic molten phase with (B) 5 to 300 parts by weight of glass fibers with an average fiber diameter of 3 to 15 μm, and in which the weight average fiber length is in a range of 0.02 to 0.55 mm, the proportion of glass fibers with a fiber length exceeding 1 mm is 0 to 15% by weight, and the proportion of glass fibers with a fiber length of 0.1 mm or less is 0 to 50% by weight, is injection-molded, and the flow length during injection molding, the shrinkage ratio of a molded product, surface impact strength, and the like have been obtained.
However, according to this technique, the weight ratio and average fiber length of the glass fibers are not controlled freely in desired glass fiber filling.